Step 3: Stretch the Bottom Section
1. Rub a small amount of petroleum jelly on the bottom of the full can.
2. Carefully insert the bottom of the full can in to the cut bottom from the first can.
3. Using a small piece of plywood or the like, apply firm and even pressure to force one can in to the other.
note: Do this step incrementally; Press the can in a little way and let the pressure build up push it back out. then repeat until you can force the can about half way in to the bottom section.